A vertical antenna, in its simplest form, is electronically equivalent to one-half of a dipole antenna stood on end. When the antenna is mounted close to the ground, the earth below provides the other half of the dipole. Typically, the capacitance between the vertical radiator and the ground causes return currents to flow along the surface of the earth back to the transmitter.
The efficiency of a vertical antenna is greatly improved if wires which extend radially outward from the vertical element of the antenna are used to enhance conductivity. The radial wires may be left on top of the ground, or they may be buried if the antenna is located in a high traffic area. It is preferable to provide as many radial wires as possible, with often times thirty-two or sixty-four wires being employed.
Typically, the radially extending wires are mounted to a circular plate which is carried by, but electrically isolated from, the vertical tower. The feed line, or coax, then must be connected such that its outer braid is attached to the radial wires, and its center core is connected to the vertical tower. The prior art antennas do not provide any convenient manner in which to make these connections, and thus, the antenna installer is left to his own devices.
Moreover, the prior art radial mounting plates are deficient in that where a large number of radial wires are to be utilized, it is difficult to attach them to the plate. Usually, with the conventional circular plates, mounting holes or other devices are provided at the circumferential periphery of the plate. However, unless the plate is of a large diameter, it is difficult to attach a large number of wires at the periphery because they are spaced so close together. Providing a plate with a larger diameter is a possible solution, but not the most desirable solution in that such increases the size of the plate and increases the cost thereof.